Table 1.

Distention in CTC examinations from four institutions as assessed by automated QA software. Numbers are percentage of colonic length (±standard deviation) having distention greater than or equal to 2 cm. Institution 3 had the greatest distention in the prone position and Institution 4 had the greatest distention in the supine position, although the differences for a particular position across institutions were not statistically significant.

Institution	Number of Patients (n = 105)	Prone	Supine
1	28	84.8 ± 16.2†	72.1 ± 20.5†
2	26	89.0 ± 15.5‡	81.1 ± 18.2‡
3	23	89.8 ± 10.4**	73.2 ± 19.1**
4	28	88.8 ± 15.5	83.1 ± 18.7
Average	26.3	88.0 ± 14.7*	77.5 ± 19.5*

^*p < .001

^†,**p < .01

^‡p < .05 by paired t-test